Astronomy is filled with references to Roman and Greek mythology and Mars is no different. The Red Planet, named for the Roman god of war, has two small moons named Phobos (Fear) and Deimos (Panic). Experts believe the two objects to be captured asteroids. The larger of the two — Phobos — orbits extremely close to Mars, a mere 5,800 kilometers (compare to Earth's Moon at 400,000 kilometers) above the surface. The grooves in the moon may indicate the gravitational draw from Mars, showing the first signs of Phobos' disintegration into a ring around Mars. [Learn more about Phobos.]